Improvement in sewing-machines



W. G. BEGKWITH.

Sewing-Machine. N0,^I67,382 Patented Sept. 7,1875.

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N. PETERSA PNOTO-LITHOGRAPMEv WASHINGTON, D C.

ATET

"FFIC IMPROVEMENT IN SEWING-MACHINES.

Specification forming part of Letters Patent N0. 167,382., dated September 7, 1875; application filed January 30, 1875.

To all whom it may concern:

Be it known that I, WILLIAM G. BECK- WITH, of Newark, Essex county, New Jersey, haveinvent-ed certain Improvements in Sewing-Machines, of which the following is a specification My invention relates to that class of doublethread machines in which the stitch is formed by the under thread being interlooped with the upper by means of a reciprocating needle or hook; and it consists in a novel construetion, combination, and arrangement of parts, which have for their object to simplify said machines and improve their operation.

The drawing, which is a view underneath the machine, shows this invention as applied to, and operating' with, the machine patented to lne April 18, 1871, No. 113,724, May 21, 1872, No. 126,921, and November 26, 1872, No. 133,351.

A is part of the frame or bedplate of the machine 5 B, the cloth-plate secured thereto; C, a lever pivoted to the bed-plate at a, and which is oscillated on its pivot by the means described in Letters Patent No. 133,351. F is the under needle or looping-hook, which interloops the under with the upper thread.

1t is secured to the short arm or shank D,

which rocks on the pivot b. This needle is of the shape shown in the drawing, its curved portion being very nearly an arc of a circle, having the point b as a center, and b F as its radius. The outer curve oi' the needle F has a longitudinal groove, o, for the thread to lie in when stretched on the hook,and this groove is bridged or has eyes to retain the thread. E is a link connect-ing the hook shank or arm D with the lever C. The motion of the lever' thus imparts to the hook a quick oscillating or rocking motion in a horizontal plane and in the arc of a circle, having the pivot b as its center, and b F as its radius. The motion of the under needle is considerable in extent, it moving in an are of about eighty degrees. Thus it will be perceived that the object of the parts described is not merely to impart a reciprocating motion to the under needle, but to swing or oscillateit through an arc (of c011- siderable degree), of a circle, of which the curve of the needle itself is an arc, ror nearly so. It will be further seen that the lever C under needle or hook H and the tension-disks G affects the operation ot' the machine, and it is found in practice that the most advantageous location for the tension-disks varies considera bly in different machines constructed according to my invention, no matter how nearly alike all the parts may be, and to render the tension adjustable in relation to the hook it is mounted on the extremity of the slotted bar H, which is secured to the bedplate A by means of the screw d, which passes through the slot inthe bar. I is a spindle, on which the under spool of thread turns, and is held by the piece of rubber tubing' e. f is the hole in the cloth-plate through which the upper or sewing needle passes. The under thread is taken from the spool X, carried between the tension-disks, and thence to the hook F, being entered at the eye at the bend of the hook, then under the bridge h, and finally passed through the eye at the point.

The mannerin which the two needles cooperate and the threads loop together is well known in the art, and need not be set forth herein.

I claiml. The combination of the hook or under needle secured to the shank D, pivoted directly to the bed-plate A on its under' side, lever C, similarly pivoted and working in substantially the same plane with the shank D, and the link F, connecting the two, constructed and operating substantially in the manner described and specified.

2. The combination ofthe tension Gr and the slotted bar H, whereby the tension is rendered adjustable in its relative position to the hook or under needle, substantially in thev manner described and specified.

WM. Gr. BEOKWITH.

Witnesses:

E. H. JOHNSON, J. KOHLER. 

